[170] [For Fritz Müller’s application of this principle to the case of certain groups of Brazilian butterflies see [Appendix II]. to this Part. R.M.]
[171] [The slight variability in the colour of this pupa, opens up the interesting question of the photographic sensitiveness of this and other species, which is stated to cause them to assimilate in colour to the surface on which the larva undergoes its final ecdysis. Some experiments upon this subject have been recorded by Mr. T. W. Wood, Proc. Ent. Soc. 1867, p. xcix, but the field is still almost unexplored. R.M.]
[172] “Über den Einfluss der Isolirung auf die Artbildung.” Leipzig, 1872, p. 20.
[173] In some instances Deilephila Lineata has also been seen by day hovering over flowers.
[174] It is true that I only reared one brood, but from this fifty specimens were obtained. It would be interesting to know whether this variety of the caterpillar is distributed over the whole of Southern Europe.
[175] In this sense Lubbock says:—“It is evident that creatures which, like the majority of insects, live during the successive periods of their existence in very different circumstances, may undergo considerable changes in their larval organization in consequence of forces acting on them while in that condition; not, indeed, without affecting, but certainly without affecting to any corresponding extent, their ultimate form.”—“Origin and Metamorphoses of Insects,” London, 1874, p. 39.
[176] “Grundzüge der Zoologie,” 1875.
[177] [Lepidopterists are of course aware that even these distinctions are not absolute, as no single character can be named which does not also appear in certain moths. The definition in this case, as in that of most other groups of animals and plants, is only a general one. See, for instance, Westwood’s “Introduction to the Classification of Insects,” vol. ii. pp. 330–332. Also some remarks by C. V. Riley in his “Eighth Annual Report” on the insects of Missouri, 1876, p. 170. With reference to the antennæ as a distinguishing character, see Mr. A. G. Butler’s article in “Science for All,” 1880, part xxvii. p. 65. R.M.]
[178] The genus of Morphinæ, Discophora, possesses hairs very similar to those of the genus Cnethocampa belonging to the Bombycidæ.
[179] [The larvæ of genera 14, Phyciodes, and 35, Crenis, are likewise spiny. See Edwards’ “Butt. of N. Amer.” vol. ii. for figures of the caterpillar of Phyc. Tharos: for notes on the larvæ of Crenis Natalensis and C. Boisduvali see a paper by W. D. Gooch, “Entomologist,” vol. xiv. p. 36. The larvæ of genus 55, Ageronia, are also spiny. (See Burmeister’s figure of A. Arethusa, “Lép. Rép. Arg.” Pl. V. Fig. 4). The larvæ of genus 98, Aganisthos, also appear to be somewhat spiny (see Burmeister’s figure of A. Orion, loc. cit. Pl. V. Fig. 6), and this raises the question as to whether the genus is correctly located in its present position. The larvæ of the following genera figured in Moore’s “Lepidoptera of Ceylon,” parts i. and ii., are all spiny:—6, Cirrochroa (Pl. XXXII.); 7, Cynthia (Pl. XXVI.); 27, Kallima (Pl. XIX.); and 74, Parthenos (Pl. XXIV.). Many species of caterpillars which are spiny when adult appear to be spineless, or only slightly hairy when young. See Edwards’ figures of Melitæa Phaeton, Argynnis Diana, and Phyc. Tharos (loc. cit.) and his description of the larva of Arg. Cybele, “Canad. Entom.” vol. xii. p. 141. The spiny covering thus appears to be a character acquired at a comparatively recent period in the phyletic development. R.M.]